There have been many definitions proposed for Bio diversity but at its simplest level it is defined as the number of species occurring in a location. This diversity includes species with similar genetic make-up and others that have evolved on different evolutionary lineages. The bio diversity of an area can be defined by three attributes. Firstly, the composition refers to the richness the plant life as well as its relative abundance. Secondly, is the structural attribute of biodiversity, that is the density, height and layers of the vegetation. As well structural attributes refer to size, shape and the spatial arrangement of the plant life. Thirdly, is the function of the vegetation. It can serve to support other plants, as a food source for other life or simply for oxygen production.
Ecosystem productivity is a function of an area's biodiversity. This is so because biodiversity leads to a greater number of interspecies connections (interactions). With all of these interactions the system contains more pathways for the flow of energy and the cycling of nutrients. The result is a system that is more resistant to disturbance (droughts, flooding, extreme weather).
CE vs Ecol vs EE.
The first area in which they differ is their view on the role that humans play. CE sees humans as being central; the entire discipline revolves around the human interactions. Ecology sees humans as being very minor; humans are sees as just another species among the animal kingdom. While, EE recognizes the role of humans as central but also acknowledges the interactions that we have with our environment and the other species with in it. The second area in which the disciplines differ is the time span CE takes a very myopic look of the future and does not look beyond 50 yrs. While EE and Ecol take a much broader view and the time span reaches from yrs to centuries (EE takes a multi-scale view). Another important difference is the disciplines view of technology.